1. Flowers only in the axils of merely serrate leaves (i.e., plant heterophyllous); common.
1. Flowers in the axils of pectinate leaves (i.e., all leaves pectinate); very rare.
All species found in Proserpinaca
MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. April 29, 2017. http://michiganflora.net/genus.aspx?id=Proserpinaca.